I didn't know there was an issue with Jims Audio, proir to buying the boards. If they were available at the diy store, at the time of purchase, I certainly would have gone in that direction.
Maybe there should be a sticky about which sources are approved/not approved?
Just wanted to point out to anyone watching that the store has boards to facilitate the design that was created by Nelson. I know many folks dont realize that Jim is basically pirating this stuff, so thought it worth mentioning. It would seem reasonable to assume that any design you see that originated on this forum should be acquired through the forum if possible. It facilitates the growth of this website and increases potential for other to find the site and begin to enjoy audio with full support and not just a one off sale. You are doing a excellent job with your build and will find lots of help here if you need it. Jim's, not so much.
Looks like two centipedes on my kitchen table.
I have everything exept the preamp fets (2sj74 / 2sk170). I can find Toshiba 74s and Panasonic 170s. Does it matter if I mix and match manufacturers? Or is there an acceptable substitute for these discountinued transistors of equivilant quality and performance?
BTW, I ended up fabbing a 2" square copper cold plate for the bridge rectifiers.
I have everything exept the preamp fets (2sj74 / 2sk170). I can find Toshiba 74s and Panasonic 170s. Does it matter if I mix and match manufacturers? Or is there an acceptable substitute for these discountinued transistors of equivilant quality and performance?BTW, I ended up fabbing a 2" square copper cold plate for the bridge rectifiers.
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Sadly, I agree with 6L6, with a 99 44/100's % certainty, your transistors probably are rip-off's, restamped as 170's and 74's. A quality class A amp with demanding power loads is not the place to use fakes.
You've populated the PCBs nicely..... Unfortunately, how are you desoldering skills? (If you want to remove your power MOSFETS, best to cut their leads and then put each lead from the PCB while applying heat. You'll trash the semiconductors [not much use, anyway] but chances are you can save the PCBs)
d:Sadly, I agree with 6L6, with a 99 44/100's % certainty, your transistors probably are rip-off's, restamped as 170's and 74's. A quality class A amp with demanding power loads is not the place to use fakes.
I don't have these yet. Still searching.
You've populated the PCBs nicely..... Unfortunately, how are you desoldering skills? (If you want to remove your power MOSFETS, best to cut their leads and then put each lead from the PCB while applying heat. You'll trash the semiconductors [not much use, anyway] but chances are you can save the PCBs)
I guess I am missing your point. Everything on these boards came from Digikey or Arrow.
Understood. International trade and Ebay in particular is the wild, wild west of business. A good rule of thumb is to try to stay away from anything brand name with an Asian mailing address. (I know, I know, I shouldn't have bought Jim's Audio PCBs.).
As for my soldering/desoldering: I can keep up with the best 14 year-old Chinese girls.
Nope, no Ebay Toshibas for me!
2bz said:
Yes. He is basically the last 'known good' source that sells just the small Jfets.
Hannes (member " h_a ") has legitimate Toshiba K170/J74 but due to his limited amount, will only sell them in a complete transistor kit for an amp. He won't jell just the Jfets. (A good decision, in my opinion.)
The real question is going to be when (not if) Linear Systems can get their J74 to market. I have a small amount of samples, they (and their K170) work wonderfully in these circuits.
In the time being, my suggestion is to buy from Spencer the amount you need, and then a few more for future projects. You will always be able to sell them on the DIYaudio swap meet if you don't use them.
It's still cheaper than tubes...
Yeah but toobs are better and they glow without letting the smoke out ..
An Hybrid F5T, now we talking ....!!!
Oh, you said TOOBS! I got distracted there for a second.
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